I REALLY wouldn't go all in for a Quarterback that hasn't been proven. Garappolo played in what, 2 games? And suddenly he's great? Even Osweiller himself did more than that.
'wasting' a first round pick for a QB would obviously be bad, but at least you won't get stuck with a massive contract. Hell, Brady himself was a sixth rounder. Russell Wilson was a third rounder. I could go on and on.
I can understand that teams would be willing to roll the dice that Garappolo is ready to be a starting QB, but to give him a massive contract for the job would be insane. Another factor that I haven't even mentioned is that Garappolo performed well for those two games... while playing for the Patriots. The Browns are much worse than the Patriots, even if you took Tom Brady out of the picture.
I don't know who will the Browns next QB. Hell, at this point they may as well keep RGIII. He's certainly not good, but there are plenty of starting QBs that are just as bad. They definitely shouldn't give their next starting QB a massive contract unless he's already a proven winner. If Aaron Rodgers shows up and demands a ton of money of course they should give it. Someone who has barely proven anything, don't do that.
edit: I also want to address the argument 'no QB in this draft is good.' We had this same talk last year. Prescott seems capable. Wentz seems good. I'm sure there are others as well that I'm forgetting, and some of them may simply need more than a year.
Then the year before that. Once again there was talk that all the QBs suck. Mariota seems decent enough. Winston might be even better.
The Browns wouldn't even have to sacrifice draft picks to get the top pick. They could get any QB they want. Even then, I'm not necessarily saying they should do it. But it definitely wouldn't be any worse than paying someone a ton of money that hasn't proven anything.